Coil spring elongated struts incorporated by reference herein utilize compression springs; however, these struts are not effective in controlling and selectively dampening the motion of the member to which they are attached. The prior art method for controlling the motion of an extendable strut is to match the compression spring rod loads to the application load, such as the weight of an automobile hood or trunk. Due to design limitation it is not always practical to exactly match or offset the load of the movable strut as it swings through its arc of movement. Consequently, closing speed of the hood or trunk lid varies throughout the movement stroke of these devices. There is a need to control motion of movement at a desired rate in various positions of the total travel.